McQuades Biology Connection - Home



The Theory of EvolutionWhy Its Important: Evolution is the key concept to understanding biology. It explains the _______________ of species and predicts _________________ObjectivesVocabularyIdentify several observations that led Darwin to conclude that species evolve.Relate the process of natural selection to its outcome.Summarize the main points of Darwin’s theory of evolution by natural selection as it is stated today.Contrast the gradualism and punctuated equilibrium models of evolution.PopulationNatural SelectionAdaptationReproductive IsolationGradualismPunctuated equilibriumDarwin Proposed a Mechanism for EvolutionIn 1859, the English naturalist Charles ___________ published convincing ______________ that species evolve, and he proposed a reasonable mechanism explaining ________ evolution occurs. Like all scientific theories, the theory of evolution has developed through decades of scientific ________________ and _____________________. Darwin made many of his observations while traveling around the world on a ship called the _____________________Science Before Darwins VoyageIn 1859, the English naturalist Charles ___________ published convincing ______________ that species evolve, and he proposed a reasonable mechanism explaining ________ evolution occurs. Like all scientific theories, the theory of evolution has developed through decades of scientific ________________ and _____________________. Darwin made many of his observations while traveling around the world on a ship called the _____________________.We now know that individuals cannot gain new adaptations during their lifetime, rather they are ________________________ Ex: giraffes do not acquire long necks by reaching for leaves on treesHowever, Lamarck did correctly point out that changes in species are due to their ______________________ conditions. Ex: If around tall trees, giraffes with longer necks will survive better than ones with short necksDarwins ObservationsOn the _____________________ islands, Darwin found evidence that challenged the traditional belief that species are unchanging. This group of islands is located about 1000km (620 mi) off the ________________ coast of South America. On the islands, Darwin noticed that many of the plants and animals _____________________ those of the nearby coast of South America.Darwin proposed that after these organisms ______________________ to the islands, they changed ___________________ overtimeHe later called this change “descent with ____________________” or evolutionExample: The evolution of different bird beaks based on the ________ available in the _________________4038600257810Why might the large ground finch be a good seed eater?Why might the large ground finch be a good seed eater?Darwin also found ________________ of extinct armadillos in South AmericaThese fossils _________________ resembled, but were not identical, to armadillos living in the areaWhen Darwin returned home, he continued to study his findings for two _____________. He was certain that evolution occurred, he just didn’t know _______.Growth of PopulationsThe key that unlocked Darwin’s thinking about how evolution takes place was an essay written in 1798 by the English economist Thomas __________________.Malthus suggested that human populations do not grow _________________ because death caused by disease, war, and famine _____________ population growth.In the study of biology, a population consists of all the individuals of _______ species that live in a specific geographical __________ and that can ______________.If populations grow ________________, they show an ____________________ pattern of growth3276600203200This growth pattern is alsocalled _____ shapedgrowth and continuallyincreases as the populationgrowsCommon in organismsthat reproduce ________________The growth of most larger organisms is slowed or “checked” by ________________ factors, like __________________, __________________, _________________, and __________________Growth usually stabilizes at a population’s2514600-1809760__________________________________ This growth is called ____ shaped growth andis common in organismswith ______________ life spansWhen Thomas Malthus wrote his paper, he thought that human population growth would soon begin to _________ down, due to limiting factors. He probably would have been correct, if the ________________ revolution soon did not occurBetter technology made it easier for humans to survive and we have been showing _____ shaped growth ever sinceAfter reading Malthus’s essay, Darwin recognized that many species produce _________ offspring, but their population growth is still slowed by limiting factors like ___________________and…individuals that have physical or behavior _________________ that are better adapted to their environment are more likely to ___________ and will __________________ more successfully than those that do not have such traitsEvolution By Natural SelectionRemember, adaptations and traits are controlled by ____________, which are inheritedAn adaptation is a feature that has become common in a population because the feature provides a selective ____________________ in a specific __________________Darwin called this differential rate of reproduction _______________ ____________________.In ________, Darwin finally wrote down his ideas about evolution and natural selection in an early outline that he showed to only a ______ scientists he knew and trusted.Darwin decided to publish after he received a letter and essay in ________ from another naturalist named Alfred Russel ________________ , who also supported the idea of evolution by natural selection.Darwin’s published work was a book called…________________________________ by Means of Natural SelectionMany people were deeply _________________ by Darwin’s theory…but it is supported by four major points…_____________________ exists within the genes of every population or species.In a particular environment, __________ individuals of a population or species are better suited to survive and have more offspringOvertime, the traits that make certain individuals of a population able to survive and reproduce tend to ______________ in that populationThere is overwhelming evidence from ____________ that living species evolved from organisms that are ______________Darwins Ideas UpdatedDarwin’s ideas are further supported by the discovery that an organism’s traits are determined by the _______________ that they _________________So, evolution occurs in a _________________ when the _______________ of certain alleles increases or decreases over time. _________________ and the ________________ of alleles that occurs during sexual reproduction provide an endless source of new _________________ for natural selection to act uponKeep in mind that most mutations are ______________, but if the mutation is beneficial, it will end up __________________ in a populationHow are New Species Formed?Populations of the same species living in different locations tend to evolve in different __________________.When members of a population became separated physically or _____________________, they are also _________________ isolated because they can no longer ________What are some examples of geographical structures that can separate a population?As members of a divided population reproduce separately, DNA __________________ or changes in mating _______________ may prevent them from _________________ even if they are in the same locationWhen members of a population can no longer interbreed, they are considered _______________ speciesExample… A squirrel population became isolated in different areas of the Grand Canyon429577546355In one population, squirrels with _________ _____________bellies were more successful, and in another population squirrels with ____________________ bellies were more successfulIn one population, squirrels with _________ _____________bellies were more successful, and in another population squirrels with ____________________ bellies were more successfulA similar pattern of evolution was observed in peppered moths52482753136900Lighter variations became more prevalent in England’s country side, while darker variations became more prevalent in England’s cities…Hypothesis?The genetic darkening of a population due to pollution has been coined industrial __________________Melanin – pigmentThe Tempo of EvolutionFor decades, most biologists have understood evolution as a _____________ process that occurs continuously .This model of evolution is called ____________. Another model of evolution, in which periods of ___________ change in species are separated by periods of little or _____change, is called ___________________ ____________________Usually seen after major _______________ changes and mass ___________________Identify several observations that led Darwin to conclude that species anisms on the Galapagos Islands?Armadillo fossils in South America?Relate the process of natural selection to its outcome.Summarize the main points of Darwin’s theory of evolution by natural selection as it is stated today._____________________ exists within the genes of every population or species.In a particular environment, __________ individuals of a population or species are better suited to survive and have more offspringOvertime, the traits that make certain individuals of a population able to survive and reproduce tend to ______________ in that population There is overwhelming evidence from ____________ that living species evolved from organisms that are ______________Contrast the gradualism and punctuated equilibrium models of evolution.Evidence of EvolutionObjectivesVocabularyDescribe how the fossil record supports evolution.Summarize how biological molecules such as proteins and DNA are used as evidence of evolution.Infer how comparing the anatomy and development of living species provides evidence of evolution.PaleontologistVestigial StructureHomologous structureEvidence that supports the theory of evolution comes from different sources…______________________________________________________________________________Fossils provide an actual _____________ of Earth’s past life-forms and evidence that indicates _____________ over timeAfter noticing changes in fossils, Darwin predicted that _____________________ forms between the great groups of organisms would be discovered…While the fossil record is incomplete, some intermediate fossils have been found between…Fishes and _______________________Reptiles and _____________________Reptiles and ___________________________The fossil record has led most scientists to agree that….1. Earth is about 4.5 _______________ years old.2. Organisms have inhabited Earth for _______ of its history.3. All organisms living today share _______________ ancestry with earlier, simpler life-forms, based on the principle of ____________Formation of Fossils_______________________ are scientists who study fossils._________ radiometric dating and relative dating are used to arrange fossils in ______________ from oldest to youngestEvidence of Whale EvolutionFor example, whales are thought to have evolved from extinct, four-legged mammals called ____________________Fossils indicate that traits helpful for ___________________ may have been passed alongModern whales have forelimbs that are ________________ and hind limbs that have been reduce to only a ________ bonesThe fossil record is incomplete because not all organisms are preserved…For fossils to form, dead organisms must quickly be covered in layers of sediment before they ___________________Fossils also only form in layers of ____________________ rock, which forms at relatively ________ temperatures and pressures _____________________ rock, which forms at _______________ temperatures and pressure, _________________ fossilsAnatomy & DevelopmentComparisons of the anatomy of different types of organisms often reveal basic ___________________ in body structures even though the structure’s _____________ may differ slightly between organisms.Similar structures, called ________________ structures, indicate a _______________ ancestryWhat is similar about these homologous structures?Sometimes structures are present in an organism, but are __________________ in size and either have ______ use or a ___________ important function than they did in a previous ancestor…Examples…Whale hind limb bonesOstrich wingsHuman appendixVestigial snake feet (buds)Embryonic DevelopmentThe evolutionary history of organisms is also seen in the development of _______________________.At some time in their development, all vertebrate embryos have a __________________, ______________________ that become limbs, and pharyngeal pouchesThe tail remains in __________________ adult vertebrates. Only adult fish and immature amphibians retain pharyngeal pouches which contain their ___________________________.Biological MoleculesDNA and ProteinsAs species evolve, changes should have become a part of their __________________ instructions. Therefore, more and more changes in a gene’s _______________ sequence should build up over time.Since DNA codes for the production of _________________species that have descended from a recent common ancestor should have _______________ amino acid differences between their proteins than more distant species.Hemoglobin ComparisonWhich organism differs most from humans according to the type of amino acids present in its hemoglobin protein?And the least different from humans?Describe how the fossil record supports evolution.Summarize how biological molecules such as proteins and DNA are used as evidence of evolution.Infer how comparing the anatomy and development of living species provides evidence of evolution.AnatomyDevelopmentEvolution of PopulationsObjectivesVocabularyIdentify four elements in the process of natural selectionDescribe how natural selection has affected the bacteria that cause tuberculosisRelate natural selection to the beak size of finchesSummarize the process of species formationIdentify the Hardy-Weinberg principleDescribe the five forces that cause genetic change in a populationIdentify why selection against unfavorable recessive traits is slowContrast directional and stabilizing selectionDivergenceSpeciationSubspeciesHardy-Weinberg principleGene flowNonrandom matingGenetic driftNormal distributionDirectional selectionStabilizing selectionNatural Selection at WorkThe process of natural selection is driven by four important points that are true for all real populations:1. All populations have genetic ____________________.2. The environment presents _____________________ to successful reproduction.3. Individuals tend to produce ________ offspring than the environment can support.4. Individuals that are ___________ able to cope with the challenges presented by their environment tend to leave more offspring than those individuals less suited to the environment do.In some instances, natural selection can be observed in ___________ periods of timeWhen small organisms with short life spans, like _____________ or _____________ become resistant to ______________ or ______________When organisms are exposed to different _______________Antibiotic ResistanceThe lung disease tuberculosis (TB) is caused by the bacterium _________________ _______________.In the 1950s, two effective _________________, isoniazid and rifampin, became available to treat TB.In the late _______, however, _______ strains of M. tuberculosis that are largely or completely _______________ to isoniazid and rifampin appeared….Evolution of Antibiotic ResistanceRifampin normally kills bacteria cells by binding to RNA polymerase, which will prevent ______________However, TB bacteria began passing on a ________________ that prevents rifampin from binding to the polymerase.So, TB bacteria with the mutation were able to _____________ treatment with the antibiotic, leading to the evolution of rifampin resistance in M. tuberculosis.Evolution of Darwins FinchesDarwin collected 31 specimens of finches from three ___________ when he visited the Galápagos Islands.All in all, he collected nine different species that were all very similar except for their _________Darwin suggested that they all evolved from an original _______________ species that changed as different populations accumulated adaptations to different ____________ sources.A study of the finches was carried out over ____ years beginning in 1973 by Peter and Rosemary ____________ of Princeton University.They discovered that during drier years, birds with __________ beaks survived better because they could eat ___________ seeds…340995062230But during ______ years, birds with ___________ beaks survived just as well because the seeds are ______________So the beaks of bird populations did ______________ in response to the ___________ food supplyBut during ______ years, birds with ___________ beaks survived just as well because the seeds are ______________So the beaks of bird populations did ______________ in response to the ___________ food supplyFormation of New SpeciesThe formation of new species, called _________________, occurs in ___________.The accumulation of differences between groups is called _________________.Adaptive RadiationWhen an original ancestor has diverged into many different species over time, the ancestor has gone through a special type of divergence, called ______________1590674189865 ______________Example…Darwin’s finchesForming SubspeciesDivergence occurs as populations of the same species differ _______________ because of adaptations to different living ______________This leads to the evolution of _______________, which can still ________________, but they represent the first steps towards speciationRemember, separate species cannot interbreed….This might mean that they… ______________ cannot mateDo not produce _____________ offspringAre isolated because they have different ____________ seasonsProduce ______________ offspringExample….The offspring of a donkey and a horse is called a ____________This hybrid offspring is _____________, so donkeys and horses are considered separate speciesExample…A similar situation applies to lions and tigersThe offspring of a male lion and female tiger is called a __________The offspring of a male tiger and female lion is called a ______________The male hybrids are ________________, so ligers cannot interbreed with other ligers, as tigons cannot interbreed with other tigons, so lions and tigers remain classified as ________________ speciesFurthermore, tigers and lions do not live in the same _____________ so they don’t reproduce together _______________Hardy Weinberg PrincipleAfter studying Mendel’s work regarding genetics, scientists wondered if dominant traits would randomly or ________________ replace recessive alleles in a populationIn 1908, an English mathematician named G. H. _____________ and a German physician named Wilhelm ______________ devised a mathematical equation that allows us to keep track of the ________________ in a population p2 + 2pq + q2 = 1p2 = frequency of homozygous _____________ alleles2pq = frequency of _________________q2 = frequency of homozygous ______________ allele*****All of the frequencies must add up to _____ p2 + 2pq + q2 = 1So, for example, the frequency of individuals with cystic fibrosis (cc) is 0.00048In the equation above, where would this number be plugged in?Then, you can determine the rest of the frequencies __________________Hardy and Weinberg determined that allele frequencies do _____ change from population to population, unless the population is acted on by a process that ____________ particular allelesSo for example, a lethal dominant allele does not become more ____________ just because it is dominantThis discovery, called the Hardy-Weinberg ______________, states that allele frequencies do not change unless ___________________ forces act on a populationFive evolutionary forces frequently act upon the all of the genes in a population called a gene _______These forces are…_____________________________________________________________________________________Mutations:Mutations in _____ affect the codons in mRNA produced during ________________Recall, however, that several codons code for the same amino acid, so not all mutations affect _____________ synthesisMutations rates in populations are usually very ______________, but they still provide new variation in a population Gene FlowGene flow is the movement or ______________ of alleles into or out of a populationImmigration = new alleles ___________ a populationEmigration = alleles ____________ a populationExample…If tall individuals leave a population, what kind of alleles will be left?Nonrandom MatingNonrandom mating occurs when organisms chose their mates based on certain ____________In animals, for example, females often select males based on their….____________________Ability to gather ________ or provide _____________Female widowbirds prefer males with ________ tails. How will this change the alleles for tail length over time?Genetic DriftOccurs when the allelic frequencies in a population are altered by __________ eventsThe effects of genetic drift are seen more often in _______________ populations because their gene pool is _______________ Example…Imagine that there is a bird population containing 90 red birds and 10 white birds. A hurricane blows 10 birds off of the mainland which end up on an island….____ of these birds are red and _____ are whiteDue to chance, the allele frequencies of the 10 ___________ birds of the new island population are drastically different from birds on the mainlandThis type of genetic drift is often called the ________________ effectNatural SelectionFavorable traits are caused by genes, but natural selection acts upon the __________ which is a phenotypeSo, for example, natural selection cannot eliminate a ______________ disease like cystic fibrosis, because heterozygous carriers have the same ______________________ as homozygous dominant individuals There are also different __________ of natural selection that affect gene pools differently________________ selection________________ selectionDisruptive selectionDirectional SelectionSelects for _____ extreme version of a trait, so the population is said to be moving in one ___________Example….Why might woodpeckers with long beaks be selected for?Stabilizing SelectionOccurs when individuals with ____________ variations of a trait are selected forExample…spider sizeBirds prefer to eat _____________ spidersSmall spiders do not __________ prey well______________ sized spiders survive the bestDisruptive SelectionWhere both extremes of a trait are selected for and the average is selected againstCan lead to speciation over timeWhy might very large beaks or very small beaks be an advantage over medium sized beaks?Identify four elements in the process of natural selection________________________________ of offspring________________________________ variation________________________________ to survive________________________________ reproductionDescribe how natural selection has affected the bacteria that cause tuberculosisRelate natural selection to the beak size of finches…Which type of beak enabled survival in dry environmentsDid beak type affect survival during wet/rainy years?Summarize the process of species formation…What is different about subspecies versus separate species?Identify the Hardy-Weinberg principle…Describe the five forces that cause genetic change in a populationMutationsGene flowNonrandom matingGenetic DriftNatural SelectionIdentify why selection against unfavorable recessive traits is slowContrast directional and stabilizing and disruptive selection ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download